Bit/word descriptions – Rockwell Automation 1771-IXE/D Thermocouple/Millivolt Input Module User Manual User Manual

Page 38

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5–2

Module Status and Input Data

Publication 1771Ć6.5.130 Ć May 1999

The complete bit/word description for the block transfer read from
the module is defined in Table 5.B.

Table 5.B

Bit/Word Description for Thermocouple/Millivolt Input

Module (1771-IXE/D)

Word

Bit

Definition

Word 1

Bit 00

Power-up bit is set to indicate that the module is waiting for its

first write block transfer

Bit 01

Out of range bit is set if one or more channel inputs are above

or below the range for which you configured the module

Bit 02

Real time sample time-out bit is set when the module updates

an input buffer with new data before the processor has read

the previous data. Monitor this bit only if you select real time

sampling.

Bit 03

Not used

Bit 04

Low cold junction temperature bit is set when the cold junction

temperature is less than 0

o

C.

Bit 05

High cold junction temperature bit is set when the cold junction

temperature exceeds 60

o

C.

Bit 06

Not used

Bit 07

EEPROM calibration values could not be read.

Bits 10-17

Polarity bit for each channel is set to indicate negative polarity:

bit 10 for channel 1 thru bit 17 for channel 8. These bits are

used in BCD and signed magnitude data formats.

Word 2

Bits 00-07

Underrange bit for each channel is set to indicate an input is

out of range: bit 00 for channel 1 thru bit 07 for channel 8.

Bits 10-17

Overrange bit for each channel is set to indicate an input is out

of range: bit 10 for channel 1 thru bit 17 for channel 8. Also set

for open channel detection.

Word 3

Bits 00-07

Low alarm bit for each channel is set to indicate the input is

less than the low limit value you entered in the corresponding

low alarm word (word 4, 6, 8, 10, 12, 14, 16, or 18): bit 00 for

channel 1 thru bit 07 for channel 8.

Bits 10-17

High alarm bit for each channel is set to indicate the input has

exceeded the high limit value you entered in the

corresponding high alarm word (word 5, 7, 9, 11, 13, 15, 17, or

19): bit 10 for channel 1 thru bit 17 for channel 8.

Words 4-11

Input for channel 1 through 8 respectively.

Word 12

Cold junction temperature in

o

C.

Word 13

Auto-calibration word.

Bit 00

Offset calibration complete bit

Bit 01

Gain calibration complete bit

Bit/Word Descriptions

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